1. Field of the Invention
The present invention relates to a fluid mixing-jetting apparatus, a fluid mixer and a snowmaker.
2. Description of the Related Art
A conventional fluid mixing-jetting apparatus of one type comprises an apparatus body having an inlet arrangement for introducing plural kinds of compressed fluids into a flow passage formed in the apparatus body and a jet outlet provided on a center axis of the flow passage of the apparatus body for jetting a fluid mixture therethrough. However, there has been a problem that the high jet pressure is required for enhancing the mixing efficiency. Thus, the apparatus becomes large in size and requires the high operation power.
A conventional fluid mixer of one type comprises an apparatus body having an inlet arrangement for introducing plural kinds of compressed fluids into a flow passage formed in the apparatus body, an outlet for discharging a fluid mixture therethrough and a twist vane type static mixer provided in the flow passage between the inlet arrangement and the outlet. However, there has been a problem that
the static mixer causes a large pressure loss when the mixing efficiency is increased, and further that the mixing efficiency is still not satisfactory.
On the other hand, a snowmaker of a snow gun type which can efficiently produce snow even at a relatively high open air temperature has been demanded. A conventional snow gun type snowmaker comprises an apparatus body having an inlet arrangement for Introducing compressed air and water into a flow passage formed in the apparatus body, and a jet outlet provided on a center axis of the flow passage of the apparatus body for jetting an air-water mixture therethrough, wherein the inlet arrangement includes an ejector structure for jetting the air into the flow passage. Upon jetting of the air-water mixture, the pressure of the compressed air (about 7 Kg/cm2) is released so that a low temperature area of about xe2x88x9240xc2x0 C. is obtained. Accordingly, the jetted waterdrops are frozen to be ice crystals through adiabatic cooling so that artificial snow is obtained.
However, the foregoing conventional snow gun type snowmaker requires a large amount of high-pressure compressed air and thus a large-size compressor with high power consumption, thereby leading to high costs.
Therefore, it is an object of the present invention to provide a fluid mixing-jetting apparatus which can improve the mixing efficiency thereof without increasing the jet pressure.
It is another object of the present Invention to provide a fluid mixer which can improve the mixing efficiency thereof without increasing a pressure loss caused at a static mixer.
It is another object of the present invention to provide a snowmaker which can easily and efficiently make artificial snow of excellent quality even at a relatively high open air temperature.
According to one aspect of the present invention, there is provided a fluid mixing-jetting apparatus comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing plural kinds of fluids into a flow passage formed in the apparatus body; and an end plate closing a downstream end of the flow passage, the end plate formed with a jet opening at a position offset from a center axis of the flow passage.
It may be arranged that the end plate is further formed with a plurality of concave portions on an upstream surface thereof so as to form the upstream surface of the end plate as a non-planar surface.
It may be arranged that the jet opening is non-circular and continuous with an inner circumference of the apparatus body at the downstream end of the flow passage.
According to another aspect of the present invention, there is provided a fluid mixer comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing plural kinds of fluids into a flow passage formed in the apparatus body; a static mixer provided in the flow passage downstream of the inlet arrangement; and a collision plate provided in the flow passage downstream of the static mixer, the collision plate having a non-circular ejection opening at an offset position thereof.
It may be arranged that the flow passage has a diameter-increased passage portion in which the static mixer is provided, the diameter-increased passage portion having a passage sectional area which is greater than that of the flow passage upstream of the diameter-increased passage portion.
It may be arranged that a downstream side of the collision plate is released.
It may be arranged that a downstream side of the collision plate has a diameter-increased passage portion whose diameter is greater than that of the flow passage downstream of the static mixer, the diameter-increased passage portion extending a given distance in a flow direction of the fluids.
It may be arranged that the static mixer comprises another collision plate disposed perpendicular to a flow direction of the fluids and a circumferential wall projecting in an upstream direction from a rim of the another collision plate.
According to another aspect of the present invention there is provided a fluid mixer comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing plural kinds of fluids into a flow passage formed in the apparatus body; a static mixer provided in the flow passage, the static mixer comprising a collision plate disposed perpendicular to a flow direction of the fluids and a circumferential wall projecting in an upstream direction from a rim of the collision plate; and a fixing disk closing a space between an outer circumference of the static mixer and an inner circumference of the apparatus body defining the flow passage, the fixing disk having a non-circular ejection opening at an offset position thereof.
According to another aspect of the present invention, there is provided a fluid mixer comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing plural kinds of fluids into a flow passage formed in the apparatus body; and a static mixer provided in the flow passage, the static mixer comprising a collision plate disposed perpendicular to a flow direction of the fluids and a circumferential wall projecting in an upstream direction from a rim of the collision plate, wherein the flow passage has a downstream passage portion whose diameter is smaller than that of the flow passage upstream of the downstream passage portion, the downstream passage portion having an upstream extended portion hermetically extended into the flow passage and hermetically closed at its upstream end by the collision plate, and wherein the upstream extended portion is formed with a non-circular ejection opening at the upstream end thereof.
According to another aspect of the present invention, there is provided a fluid mixer comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing plural kinds of fluids into a flow passage formed in the apparatus body, the flow passage having a diameter-increased passage portion comprising a diameter-increasing step and a diameter-decreasing step; and a static mixer provided in the diameter-increased passage portion, the static mixer comprising a collision plate disposed perpendicular to a flow direction of the fluids and a circumferential wall projecting in an upstream direction from a rim of the collision plate, wherein at least one of an upstream end and a downstream end of the circumferential wall is located close to corresponding one of the diameter-increasing step and the diameter-decreasing step to provide a small gap therebetween.
According to another aspect of the present invention, there is provided a fluid mixer comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing plural kinds of fluids into a flow passage formed in the apparatus body, the flow passage having a diameter-increased passage portion comprising a diameter-increasing step and a diameter-decreasing step; and a static mixer provided in the diameter-increased passage portion, the static mixer comprising a collision plate disposed perpendicular to a flow direction of the fluids and a circumferential wall projecting in an upstream direction from a rim of the collision plate, wherein one of an upstream end and a downstream end of the circumferential wall is in contact with corresponding one of the diameter-increasing step and the diameter-decreasing step, and wherein a concave portion is formed on the corresponding one of the diameter-increasing step and the diameter-decreasing step at a contact portion thereof with the circumferential wall.
According to another aspect of the present invention, there is provided a snowmaker comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing compressed air and water into a flow passage formed in the apparatus body; and a static mixer provided in the flow passage downstream of the inlet arrangement.
It may be arranged that the flow passage has a diameter-increased passage portion downstream of the inlet arrangement, and that the static mixer is disposed in the diameter-increased passage portion and comprises a collision plate having a diameter approximate to a diameter of the flow passage upstream of the diameter-increased passage portion.
It may be arranged that the flow passage has a jet-side passage portion downstream of the diameter-increased passage portion, and that a downstream end of the jet-side passage portion is closed by an end plate which is formed with a non-circular jet opening at a position offset from a center axis of the flow passage, the non-circular jet opening being continuous with an inner circumference of the apparatus body defining the jet-side passage portion.
It may be arranged that the snowmaker further comprises an open-air suction inhibiting cover disposed around the non-circular jet opening and opened In a jet direction of the compressed air and water via the non-circular jet opening.
It may be arranged that the open-air suction inhibiting cover has a funnel shape.
According to another aspect of the present invention, there is provided a snowmaker comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing compressed air and water into a flow passage formed in the apparatus body, the flow passage having a jet-side passage portion; and an end plate closing a downstream end of the jet-side passage portion, the end plate formed with a jet opening at a position offset from a center axis of the flow passage.
It may be arranged that the jet opening is non-circular and continuous with an inner circumference of the apparatus body defining the jet-side passage portion.
It may be arranged that the snowmaker further comprises a static mixer provided in the flow passage downstream of the inlet arrangement.
According to another aspect of the present invention, there is provided a snowmaker comprising an apparatus body for mixing compressed air and water and jetting the mixed compressed air and water via a jet opening; and an open-air suction inhibiting cover disposed around the jet opening, the open-air suction inhibiting cover opened in a jet direction of the mixed compressed air and water via the jet opening.
It may be arranged that the open-air suction inhibiting cover has a funnel shape.
According to another aspect of the present invention, there is provided a snowmaker comprising an apparatus body provided at its upstream end with an inlet arrangement for introducing compressed air and water into a flow passage formed in the apparatus body, the flow passage having a diameter-increased passage portion downstream of the inlet arrangement, the diameter-increased passage portion having an upstream diameter-increasing step; a collision plate provided in the diameter-increased passage portion, the collision plate having a diameter approximate to a diameter of the flow passage upstream of the diameter-increased passage portion: a circumferential wall projecting in an upstream direction from a rim of the collision plate: an end plate closing a downstream end of a jet-side passage portion of the flow passage, the jet-side passage portion located downstream of the diameter-increased passage portion, the end plate formed with a jet opening at a position offset from a center axis of the flow passage: and a collision plate moving mechanism associated with the collision plate for adjusting a gap between an upstream end of the circumferential wall and the upstream diameter-increasing step of the diameter-increased passage portion.
It may be arranged that the snowmaker further comprises a compressed air feed amount adjusting apparatus for adjusting an amount of the compressed air to be introduced into the flow passage via the inlet arrangement, and a compressed water feed amount adjusting apparatus for adjusting an amount of the compressed water to be introduced into the flow passage via the inlet arrangement.
It may be arranged that the snowmaker further comprises an open air temperature gauge, an open air hygrometer and a controller which controls the collision plate moving mechanism, the compressed air feed amount adjusting apparatus and the compressed water feed amount adjusting apparatus based on measured values of the open air temperature gauge and the open air hygrometer.